The potential for injury to individuals operating for prolonged periods in an abnormal temperature environment is well recognized and has been for a considerable period of time. Individuals such as steel mill and power plant workers, firefighters, and heavy machine operators perform duties in such environments and are exposed to considerable risk of illness and/or injury due to heat stress. These particular environments involve elevated temperatures, but exposure to undue low temperatures can also result in problems, for example hypothermia.
Past efforts to protect against such heat stress have included monitoring the environmental condition per se, that is the ambient temperature, radiant heat, humidity, etc.
It has been recognized that internal body core temperature is an accurate parameter for assessing heat stress. Continuous monitoring of the internal core temperature by means of a rectal thermometer has been proposed. In addition, there have been efforts to use skin temperature and heart rate as parameters in assessing internal core temperature.
These prior approaches have various shortcomings in that they are uncomfortable, difficult to use, and/or lack reliability and accuracy.
Among the objects of this invention are to provide accurate, reliable, easy-to-use, and/or physically unobtrusive monitoring of internal core temperature.